1. Field of the Invention
The present invention relates to a television apparatus having a liquid crystal display, and more particularly to a liquid crystal television apparatus a transmittance of liquid crystal cells of which is high and which is excellent in color reproductivity.
2. Description of the Related Art
In recent years, a television apparatus using an LCD (Liquid Crystal Display) as a display is spreading. The television apparatus having the liquid crystal display (hereinafter referred to as “liquid crystal television apparatus”) has such an advantage that the apparatus is thin in thickness, light in weight, and small in power consumption rather than the television apparatus using a conventional CRT (Cathode Ray Tube). Also, normally a backlight light source is built in the liquid crystal television apparatus, and a color video is displayed on a screen of liquid crystal cells by irradiating a light emitted from the light source to the liquid crystal cells provided in the front via a diffusing plate, a prism sheet, etc., to pass through a color filter provided to the cell.
FIG. 5 is an exploded perspective view of a display unit in a conventional liquid crystal television apparatus. Here, 1 is a rear frame that is formed of a metal plate. A wiring substrate (not shown) on which a signal processing IC is mounted is provided to the backside of the rear frame 1. Then, 2 is a reflecting sheet mounted on the rear frame 1 and is formed of a white synthetic resin plate. The reflecting sheet 2 acts to reflect lights emitted from backlight light sources 53 to 55 described later. Then, 3 is a reflection frame that is constructed by a metal or synthetic resin frame member, and its inner surface is coated in white to reflect the lights emitted from the backlight light sources. Then, 4 is a rubber spacer that serves as a buffer material when it is interposed between an upper edge of the reflection frame 3 and a liquid crystal cell 12 described later. Then, 53 to 55 are three cold cathode fluorescent tubes constituting backlight light sources, which are shaped into a U-shape respectively. Then, 63 to 65 are holders that hold the cold cathode fluorescent tubes 53 to 55 and are made of an elastic member such as silicon rubber. The holders 63 to 65 have slits 63a to 65a into which the cold cathode fluorescent tubes 53 to 55 are fitted respectively. Then, 7 is a socket into which each end portion of the cold cathode fluorescent tubes 53 to 55 is inserted. The cold cathode fluorescent tubes 53 to 55 and external circuits are electrically connected mutually via the sockets 7.
Then, 8 to 11 are optical members that guide the lights emitted from the cold cathode fluorescent tubes 53 to 55 forward (upward in FIG. 5) and are constructed by a diffusing plate 8 and a diffusing sheet 9 for diffusing the light, a prism sheet 10 for collecting the diffused lights to direct them forward, and a polarization reflecting sheet 11 for passing only the light in the particular direction out of the lights collected by the prism sheet 10 and reflecting remaining lights. Then, 12 is a liquid crystal cell that has a known structure including a pair of glass substrates, and a liquid crystal, transparent electrodes, color filters that are provided between the glass substrates. The detailed structure of the liquid crystal cell is disclosed in JP-A-2002-323698 and JP-A-2003-5175, for example. Also, the color filter is disclosed in JP-A-11-248931. Then, 13 is a front frame that is made of metal and is formed like a frame in such a manner that the front frame 13 can cover an edge portion of the liquid crystal cell 12 while leaving a portion that serves as a display screen of the liquid crystal cell 12. Then, 14 is a masking tape that is pasted onto an edge portion of the surface of the liquid crystal cell 12. The masking tape 14 prevents the lights emitted from the cold cathode fluorescent tubes 53 to 55 from leaking from peripheries of the liquid crystal cell 12.